USO0RE43567E
(19) United States (12) Reissued Patent
(10) Patent Number: US RE43,567 E (45) Date of Reissued Patent: Aug. 7, 2012
Sun et a]. (54)
INTRA-PREDICTION MODE ESTIMATION
(75) Inventors: Shijun Sun, Redmond, WA (US); Louis Joseph Kerofsky, Camas, WA (US)
(73) Assignee: Sharp Kabushiki Kaisha, Osaka (JP)
(21) Appl.No.: 12/608,848 (22) Filed:
Oct. 29, 2009 Related US. Patent Documents
Reissue of:
(64) Patent No.: Issued:
Appl. No.:
10/404,211
Filed:
Mar. 31, 2003
FOREIGN PATENT DOCUMENTS JP JP JP JP JP JP JP W0 WO W0 WO
05-183758 5-183758 08-186823 8-186823 2000 295627 2000-295627 2000-295627 WO 00/33583 WO-00/33583 W0 02/054779 WO-02/054779
A A
A1 A2
7/1993 7/1993 7/1996 7/1996 10/2000 10/2000 10/2000 6/2000 6/2000 7/2002 7/2002
2008.
European Search Report for EP Application No. 08 00 7745.6, Jan. 28, 201 1. European Search Report for EP Application No. l0 17 9562.03, Jan. 28, 201 1. European Search Report for EP Application No. l0 17 9572.2, Jan. 28, 201 1.
(2006.01) (2006.01)
(Continued)
US. Cl. .................. .. 382/236; 375/240.14; 382/239 Field of Classi?cation Search ................ .. 382/239,
382/238
See application ?le for complete search history. (56)
A
lain E G Richardson, “H.264/MPEG-4 part 10 Tutorials”, H.264/ MPEG-4 part 10: Intra Prediction, pp. 1 of 6-6 of 6, [online], Apr. 30,
Provisional application No. 60/319,390, ?led on Jul.
Int. Cl. G06K 9/36 H04N 7/12
6/2005 Kalevo et al.
3/2002 Yagishita et al. 5/2003 Teng
OTHER PUBLICATIONS
11, 2002, provisional application No. 60/319,272,
(52) (58)
2003/0081838 A1
Oct. 30, 2007
?led on May 28, 2002.
(51)
2002/0031276 A1
7,289,672
US. Applications: (60)
6,907,142 B2
METHODS AND SYSTEMS FOR IMAGE
Primary Examiner * Hadi Akhavannik
(74) Attorney, Agent, or Firm * Birch, Stewart, Kolasch &
Birch, LLP
(57)
References Cited
ABSTRACT
Embodiments of the present invention relate to methods and U.S. PATENT DOCUMENTS 6,345,121 B1 6,668,095 B2 6,765,964 B1
systems for estimating a pixel prediction mode to be used in a video encoding or decoding process.
2/2002 Matsumoto 12/2003 Rackett 7/2004 Conklin
17 Claims, 10 Drawing Sheets
\J-“M 161
B
US RE43,567 E Page 2 OTHER PUBLICATIONS
KarcZeWicZ: “Analysis and Simpli?cation of Intra Prediction”, ITU
Study Group 16iVideo Coding Experts GroupiISO/IEC MPEG &
2001 (Jan. 9, 2001, pp. 1-35, XP00108915 *paragraph ’3.4 Intra prediction mode (Intraipredimode)!* *tables 1.2”‘. Bojun Meng et al: “Fast intra prediction mode selection for 4x4 blocks in H.264” 2003 IEEE International Conference on Acoustics,
ITU-T VCEG(ISO/IEC JTC1/SC29/WG11 and ITU-T SG16 Q6),
Speech, and Signal Processing Proceedings (ICASSP), Hong Kong,
XX, XX, No. JVT-D025, Jul. 26, 2002 (Jul. 26, 2002),
Apr. 6-10, 2003 IEEE International Conference on Acoustics,
XP030005299.
Speech, and Signal Processing (ICASSP), NeWYork, NY: IEEE, US,
Sun: “Intra-Prediction Mode Ordering and Coding”, ITU Study Group 16iVideo Coding Experts Group ISO/IEC MPEG & ITU-T VCEG(ISO/IEC JTC1/SC29/WG11 and ITU-T SG16 Q6), XX, XX, No. JVT-D027, Jul. 26, 2002 (Jul. 26, 2002) XP030005301.
vol. 1 of 6, Apr. 6, 2003 (Apr. 6, 2003), pp. 111389-111392,
Joint Committee Draft (CD), Document JV T-C167, Joint Video Team (JV T) of ISO/IEC MPEG and ITU-T VCEG, May 2002. Greg Conklin, “New Intra Prediction Modes,” documentVCEG-N54
doc, ITU-T Video Coding Experts Group (VCEG) Meeting Santa Barbara, CA USA 24-28, May 2001. Minhua Zhou, “Scalable Intra Prediction,” document JV T-C033 doc, Joint Vide Team (JV T) of ISO-IEC MPEG & ITU-T VCEG Meeting Fairfax, Virginia, USA 6-10, Dec. 2001. H.26L Test Model Long Term No. 6 (TML-6) draft0. [online], ITU Telecommunications Standardization Sector Study Group 16 Video Coding Experts Group (VCEG), 2001, pp. 11-14 [retrieved on May
XPO10639091 ISBN: 0/7803-7663-3 *the Whole document*.
Joint committe Draft (CD), Document JV T-C167, Joint Video Team (JV T) of ISO/IEC MPEG and ITU-T VCEG. Greg Conklin, “New Intra Prediction Modes,” documentVCEG-N54
doc, ITU-T Video Coding Experts Group (VCEG) Meeting Santa Barbara, CA, USA 24-28. Minhua Zhou, “Scalable Intra Prediction,” document JV T-C033 doc, Joint Vide Team (JV T) of ISO/IEC MPEG & ITU-T VCEG Meeting Fairfax, Virginia, USA 6-10. Iain E G Richardson, H.264/MPEG-4 Part 10:Intra Prediction, pp. 1
of 1-7 of7, [online], 07.10.02, H.264/MPEG-4 Part 10 White Paper, [retrieved on Sep. 22, 2003], Retrieved from Internet:,//218.30.21.
30/ sc/jyWd/h264iintrapredpdf.
28, 2003].
“H.26L Test Model Long Term No. 6 (TML-6) Draft O”ITU-T Tele communication StandariZation Sector of ITU Geneva, CH. Jan. 9,
lain E G Richardson, “H.264/MPEG-4 Part 10:Intra Prediction”, pp. 1 of 1 -7 of7, [online], 07.10.02, H.264/MPEG-4 Part 10 White Paper,
2001, pp. 1-35, X00108915 *paragraph ’3.4 Intra prediction mode (Intraipredimode)!* *tables 1, 2*.
[retrieved on Sep. 22, 2003], Retrieved from Internet:,//218.30.21. 3 0/sc/jyWd/h264iintrapredpdf.
blocks in H.264” 2003 IEEE International Conference on Acoustics,
Bojun Meng, Oscar C. Au, “Fast Intra-Prediction Mode Selection for 4x4 Blocks in H.264”, ICASSP 2003 IEEE International Conference,
Apr. 6-10, 2003,IEEE International Conference on Acoustics,
(Apr. 6-10, 2003), IEEE, pp. III-389-III-392. Weigland T: “Joint Model No. 1, Revision 1(JM-IRL)” ITU Study
vol. vol. 1 of 6, Apr. 6, 2003, pp. 11389-111392, XPO10639091
Bojun Mend et al; “Fast intra-prediction mode selection for 4x4
Speech, and Signal Processing. Proceedings. (ICASSP). Hong Kong, Speech, and Signal Processing (ICASSP), NeWYork, NY: IEEE, US,
Group 16iVideo Coding Experts Group, Dec. 3, 2001 (Mar. 12,
ISBN: 0-7803-7666-3 * the Whole document*.
2001), pp. 1, 3-75, XP001086627 *paragraph ’3.4.3 Intra Prediction
Weigland T: “Joint Model No. 1, Revision 1(JM-IRL)” ITU Study
Mode (Intraipreimode) ! * .
Group 16iVideo Coding Experts Group, Dec. 3, 2001, pp. 1, 3-75,
Pan F et al: “Fast Mode Decision for Infra Prediction” Joint Video
XP001086627 *paragraph ’3.4.3 Intra Prediction Mode (Intrai
Team (JVT) of ISO/IEC MPEG & ITU-T VCEG (ISO/IEC JTC1/ SC29/WG11 and ITU-T SG-16 Q.6), Document JVT-G013, ’Online! Mar. 7, 2003 (Mar. 7, 2003), pp. 1-22, XP002325066 Retrieved from
predimode) ! * .
the Internet: URL:http://ftp3 .itu.int/av-arch/jvt-site/2003 03 Pattaya/ JVT-GO13 .doc>1retrieved on Mar. 23, 2005! “the Whole document”.
H.26L Test Model Long Term No. 6 (TML-6) Draft 0. ITU-T Tele communication Standardization Sector of ITU Geneva, CH.9 Jan.
Pan F et al: “Fast Mode Decision for Intra Prediction” Joint Video
Team (JVT) of ISO/IEC MPEG & ITU-T VCEG (ISO/IEC JTC1/ SC29/WG11 and ITU-T SG16 Q.6), Document JVT-GO13, ’Online! Mar. 7, 2003 pp. 1-22, XP002325066 Retrieved from the Internet:
URL;http://ftp3 .Itu.int/ av-arch/jvl-site/ 2003i03iPattaya/JV T G013.doc> retrieved on Mar. 23, 2005! *the Whole document*.
US. Patent
Aug. 7, 2012
Sheet 1 0f 10
FIG. 1
26
‘UOZEF-xL
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US. Patent
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Sheet 2 0f 10
US RE43,567 E
42
32 X 34
44 40
38 48
36
FIG. 3
46
US. Patent
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Sheet 3 0f 10
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US. Patent
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US RE43,567 E
Sheet 4 0f 10
Select Target Block 50
i Determine 1st Prediction Mode Used For 1st
Adjacent Block
/"\
52
i Determine 2nd Prediction Mode Used For 2nd
Adjacent Biock 54
i Determine Estimated Mode As Most Likely of 1st Mode And 2nd Mode to Produce Lesser Prediction Error /
56
FIG. 9
US. Patent
Aug. 7, 2012
US RE43,567 E
Sheet 5 0f 10
Order Set of Prediction
Modes By Prediction Error/ Likeiihood
58
i Select Target Block /
i Determine 1st Prediction Mode Used For 1st Adiacent Block A
60
62
i Determine 2nd Prediction Mode Used For 2nd
Adjacent Block /
64
i Determine Estimated Mode As Most Likely of 1st Mode And 2nd Mode to Produce Lesser Prediction Error I, 66
FIG. 10
US. Patent
Aug. 7, 2012
Sheet 6 0f 10
Order Set of Prediction
Modes According to
Likelihood of Producing A’\\ Lesser Prediction Error
l Associate Modes with Numerical Values
(Higher Likelihood ot
Lesser Error Associates /'_\\-m with Lower‘ Value)
l Determine Mode Used For
1st Adiacent Block And 4“ Associated Value
l Determine Mode Used For 2nd Adjacent Block And Associated Value
l Select Mode with Lower Associated Value as Estimated Mode
FIG. 11
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Aug. 7, 2012
Sheet 7 0f 10
US RE43,567 E
Order Set of Prediction Modes According To Likelihood of Producing /"'\ Lesser Prediction Error
78
l Associate Modes with Numerical Values
(Higher Likelihood of Lesser Error Associates
with Lower Value)
/’\8o
l Attempt To Determine Mode Used For 1st
Adjacent Block
/
/_\
82
i
Attempt To Determine Mode Used For 2nd
Adjacent Block
/ ’\ 84
158 Block Mode Data
Available
2nd Block Mode Data Available
86
88
90
r
/
Select Default '
Mode As Estimated Mode
_
Select Mode Wlth Lower /—\ Value As Estimated Mode 92
i
i FIG. 12
US. Patent
Aug. 7, 2012
Sheet 8 0f 10
US RE43,567 E
Select Prediction Mode Order /.\ 102
Determine Estimated Prediction Mode With
Adjacent Block Data /”'\_ 104
l Place Estimated Prediction Mode into Order As Mode
Most Likely To Produce Reduced Error
/ ,-\
106
FIG. 13
US. Patent
Aug. 7, 2012
Sheet 9 0f 10
US RE43,567 E
Designate/Select Prediction Mode Order
/'_\
110
i Determine Estimated Prediction Mode
/'\
‘v
112
Determine "Actuar‘ Best Prediction Mode /'_\ 114
Signal Decoder to‘ use Estimated
Prediction Mode
ls Estimated Prediction Mode Actual Best
Prediction Mode
Signal Decoder to use
Specific Mode In Prediction Mode Order
FIG. 14
116
US. Patent
Aug. 7, 2012
Sheet 10 0f 10
US RE43,567 E
Select Prediction Mode Order with 9 Modes
‘
/\ 130
Determine Estimated
Prediction Mode
/”‘\
¢
132
Determine Best Prediction Mode /'\ 134
/ 138
Signal Decoder to ( use Estimated
stimated Prediction Mode
Prediction Mode
'-=
with 1- bit
Best Prediction Mode
Designator
?
136
//_\ Eliminate Estimated Prediction Mode From Order
Signal Decoder to use Best Mode With 3 - bit
Designator
FIG. 15
140
m2
US RE43,567 E 1
2 FIG. 4 illustrates the general directions of prediction
METHODS AND SYSTEMS FOR IMAGE INTRA-PREDICTION MODE ESTIMATION
modes in an embodiment of the present invention;
FIG. 5 illustrates the general directions of prediction modes in an embodiment of the present invention;
Matter enclosed in heavy brackets [ ] appears in the original patent but forms no part of this reissue speci?ca
FIG. 6 illustrates the general directions of prediction modes in an embodiment of the present invention;
tion; matter printed in italics indicates the additions made by reissue.
FIG. 7 illustrates the general directions of prediction modes in an embodiment of the present invention;
FIG. 8 illustrates the general directions of prediction RELATED REFERENCES
modes in an embodiment of the present invention; FIG. 9 is a block diagram illustrating mode estimation in some embodiments of the present invention FIG. 10 is a block diagram illustrating mode estimation in embodiments with an ordered set of prediction modes; FIG. 11 is a block diagram illustrating mode estimation with ordered sets associated with numerical values; FIG. 12 is a block diagram illustrating mode estimation
This application claims the bene?ts of US. patent applica tion Ser. No. 60/319,272 ?led May 28, 2002 and US. patent application Ser. No. 60/319,390 ?led Jul. 11, 2002. BACKGROUND
options when some adjacent block data is unavailable; FIG. 13 is a block diagram illustrating mode order modi
Embodiments of the present invention relate to intra-pre diction for an image.
Digital video requires a large amount of data to represent each and every frame of a digital video sequence (e. g., series of frames) in an uncompressed manner. It is not feasible for
20
most applications to transmit uncompressed digital video across computer networks because of bandwidth limitations.
In addition, uncompressed digital video requires a large
25
mode is used to modify mode order using speci?c designa
amount of storage space. The digital video is normally
tors.
encoded in some manner to reduce the storage requirements
and reduce the bandwidth requirements. One technique for encoding digital video is interframe
?cation in some embodiments of the present invention; FIG. 14 is a block diagram illustrating the methods of an embodiment of the present invention in which an estimated mode is used to modify mode order usage; and FIG. 15 is a block diagram illustrating the method of an embodiment of the present invention in which an estimate
DETAILED DESCRIPTION 30
encoding. Interframe encoding exploits the fact that different
Embodiments of the present invention comprise methods and systems related to intra-prediction of images. As all
frames of video typically include regions of pixels, normally selected as x by x blocks, that remain substantially the same.
embodiments are related to intra-prediction, the terms “intra
During the encoding process a motion vector interrelates the
prediction” and “prediction” may be used interchangeably to
movement of a block of pixels in one frame to a block of
35
refer to intra-prediction processes. Embodiments of the present invention use intraframe cod
similarpixels in another frame. Accordingly, the system is not required to encode the block of pixels twice, but rather
ing or intracoding to exploit spatial redundancies within a
encoding. Intraframe encoding encodes a frame or a portion
video image. Because adjacent blocks generally have similar attributes, the e?iciency of the coding process is improved by referencing the spatial correlation between adjacent blocks. This correlation may be exploited by prediction of a target
thereof without reference to pixels in other frames. Typically intraframe encoding encodes the frame, or portions thereof,
block based on prediction modes used in adjacent blocks. A digital image may be divided into blocks for more e?i
encodes the block of pixels once and provides a motion vector
to predict the other block of pixels. Another technique for encoding digital video is intraframe
on a block by block basis. For example, in MEPG-2 the intraframe encoding makes use of discrete cosine transforms
40
45
cient processing or for other reasons. As illustrated in FIG. 1, a target block “C” 12 may be situated adjacent to adjacent
of a block of pixels and subsequent encoding of the trans
block “A,” 14 which is located immediately above target
formed coef?cients. Other intraframe encoding techniques exist, such as for example, wavelet encoding.
block “C” 12. Another adjacent block “B” 16 is located immediately to the left of target block “C” 12. Other blocks that share boundaries with target block “C” 12 may also be considered to be adjacent blocks to block “C” 12. Blocks may comprise various numbers of pixels in differ ent con?gurations. For example, a block may comprise a 4x4 array of pixels. A block may also comprise a 16x16 array of pixels or an 8x8 array. Other pixel con?gurations, including both square and rectangular arrays may also make up a block. Each pixel in a target block may be predicted with refer
In general, these techniques employ relatively large data tables for referencing prediction modes. Memory for these
50
data tables can be burdensomely expensive for many low cost
machines. Moreover, it is also burdensomely expensive to provide su?icient memory within processing devices to store the data table. Also, the resulting system has increased com
plexity with the large data table.
55
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings depict only typical embodiments of the present invention and are not therefore to be considered
60
to be limiting of its scope, the invention will be described and
may be referenced using an alphanumeric index as illustrated in FIG. 2. FIG. 2 illustrates a 4x4 target block, such as block
explained with additional speci?city and detail through the
“C” 12 comprising 16 pixels designated by lower case alpha
use of the accompanying drawings in which:
betic characters 22. Pixels in an adjacent block immediately
FIG. 1 illustrates some forms of block adjacency;
FIG. 2 illustrates a block of pixels and the adjacent pixels
for prediction; FIG. 3 illustrates general prediction mode directions;
ence to data regarding pixels in adjacent blocks. This adjacent pixel data or adjacent block data comprises the prediction modes used to predict those adjacent blocks or adjacent pix els. Speci?c adjacent pixels and pixels within a target block
65
above the target block are designated by capital alphabetic characters 24. Pixels in an adjacent block immediately to the
left of the target block are designated by capital alphabetical
US RE43,567 E 3 characters 26. The bottom right pixel 25 in an adjacent block above and to the left of the target block 12 is designated by the Mode 6: horizontal-down prediction
capital letter “Q.” Prediction modes may comprise instructions or algorithms for predicting speci?c pixels in a target block. These modes
b, h may be predicted by
may refer to one or more adjacent block pixels as described in
0 may be predicted by
a, g may be predicted by
the folloWing mode descriptions.
d may be predicted by e, k may be predicted by
Prediction Modes
f, 1 may be predicted by i, 0 may be predicted by
Mode 0: vertical prediction a, e, i, m may be predicted by A
j, p may be predicted by m may be predicted by 11 may be predicted by
b, f, j, n, may be predicted by B, c, g, k, 0, may be predicted by C
d, j, l, p may be predicted by D Mode 1: horizontal prediction a, b, c, d, may be predicted by I e, f, g, h, may be predicted by J
Mode 7: vertical-right prediction a may be predicted by
i, j, k, 1, may be predicted by K m, n, o, p, may be predicted by L Mode 2: DC prediction
20
If all samples A, B, C, D, I, J, K, L, are available, all
samples may be predicted by (A+B+C+D+I+J+K+L+4)>>3. If A, B, C, and D are not available and I, J, K, and L are
available, all samples may be predicted by (I+J+K+L+2)>>2.
25
b, i may be predicted by c,j may be predicted by d, k may be predicted by 1 may be predicted by e may be predicted by f, m may be predicted by g, 11 may be predicted by h, 0 may be predicted by p may be predicted by
If I, J, K, and L are not available and A, B, C, and D are
available, all samples may be predicted by (A+B+C+D+ 2)>>2. If all eight samples are not available, the prediction for all lama samples in the block may be 128. A block may be
alWays predicted in this mode.
30
Mode 8: horizontal-up prediction a may be predicted by b may be predicted by c, e may be predicted by
Mode 3: diagonal down/left prediction
d, fmay be predicted by 35 g, i may be predicted by
h, j may be predicted by
b, e may be predicted by c, f, i may be predicted by d, g,j, m may be predicted by h, k, 11 may be predicted by l, 0 may be predicted by p may be predicted by
l, 11 may be predicted by k, m may be predicted by 0 may be predicted by p may be predicted by (G + H + O + P + 2) >> 2
40
The ordering process, Which is based upon the likelihood of producing a lesser prediction error for each of the modes,
increases the coding e?iciently, reduces the memory require Mode 4: diagonal down/right prediction
45
m may be predicted by i, 11 may be predicted by e, j, 0 may be predicted by
a, f, k, p may be predicted by b, g, 1 may be predicted by c, h may be predicted by d may be predicted by
50
ments, and may be at least partially mathematically de?ned. Each prediction mode may be described by a general direc tion of prediction as described verbally in each of the mode titles above (i.e., horiZontal up, vertical and diagonal doWn
left). A prediction mode may also be described graphically by an angular direction. This angular direction may be expressed through a diagram With arroWs radiating outWard from a center point as shoWn in FIG. 3. In this type of diagram, each arroW and the center point may represent a prediction mode.
55
Mode 5: vertical-left prediction
a, j may be predicted by b, k, may be predicted by c, 1 may be predicted by d may be predicted by e, 11 may be predicted by f, 0 may be predicted by g, p may be predicted by h may be predicted by i may be predicted by
(C + D + 1) >> 1 (I + 2Q +A + 2) >> 2 (Q + 2A + B + 2) >> 2 (A + 2B + C + 2) >> 2 (B + 2C + D + 2) >> 2 (Q + 2I + J + 2) >> 2
m may be predicted by
(I + 2J + K + 2) >> 2
60
The angle corresponding to a prediction mode has a general relationship to the direction from the Weighted average loca tion of the adjacent pixels used to predict the target pixel to the actual target pixel location. HoWever, the modes are more precisely de?ned in the de?nitions above and in the NT stan dard. In FIG. 3, the center point 32 represents no direction so this point may be associated With a DC prediction mode. A horiZontal arroW 34 may represent a horiZontal prediction mode. A vertical arroW 36 may represent a vertical prediction
65
mode. An arroW extending from the center point diagonally doWnWard to the right at approximately a 45 degree angle from horizontal 38 may represent a Diagonal DoWn/Right (DDR) prediction mode. An arroW extending from the center point diagonally doWnWard to the left at approximately a 45
US RE43,567 E 6
5
Mode 5: Horizontal DoWn prediction
degree angle from horizontal 40 may represent a Diagonal DoWn/Left (DDL) prediction mode. Both the DDR and DDL prediction modes may be referred to as diagonal prediction
Mode 6: Vertical Right prediction Mode 7: Vertical Left prediction
modes. An arroW extending from the center point diagonally
Mode 8: Horizontal Up prediction In a second set of embodiments, as illustrated in FIG. 5, modes may be de?ned in order as folloWs:
upWard to the right at approximately a 22.5 degree angle from horizontal 42 may represent a Horizontal Up (HU) prediction mode. An arroW extending from the center point diagonally doWnWard to the right at approximately a 22.5 degree angle
Mode 0: Horizontal prediction Mode 1: Vertical prediction Mode 2: DC prediction Mode 3: Diagonal DoWn/Left prediction
from horizontal 44 may represent a Horizontal DoWn (HD) prediction mode. An arroW extending from the center point diagonally doWnWard to the right at approximately a 67.5 degree angle from horizontal 46 may represent a Vertical
Mode 4: Diagonal DoWn/Right prediction Mode 5: Horizontal DoWn prediction
Mode 6: Vertical Right prediction
Right (VR) prediction mode. An arroW extending from the
Mode 7: Vertical Left prediction
center point diagonally doWnWard to the left at approximately
Mode 8: Horizontal Up prediction
a 67.5 degree angle from horizontal 48 may represent a Ver
In a third set of embodiments, as illustrate in FIG. 6, modes may be de?ned in order as folloWs:
tical Left (VL) prediction mode. The HU, HD, VR and VL prediction modes may be referred to collectively as interme
diate angle prediction modes. Many other prediction modes may be created and
20
described using this angular description scheme. Prediction Mode Order
Mode 4: Diagonal DoWn/Right prediction
The present inventors have determined that prediction modes may be ordered in a manner generally consistent With their likelihood of producing a reduced prediction error. With
Mode 5: Vertical Right prediction 25
the prediction modes ordered according to their general like lihood of producing a lesser prediction error, the resulting
determined that the horizontal prediction mode and the ver tical prediction mode are generally more likely than diagonal prediction modes, Which are generally more likely than inter mediate angle prediction modes. In addition, a DC prediction mode (e.g., When an adjacent block is coded in inter mode) is
In a fourth set of embodiments, as illustrated in FIG. 7, modes may be de?ned in order as folloWs: 30
Mode 0: Horizontal prediction Mode 1: Vertical prediction Mode 2: DC prediction Mode 3: Diagonal DoWn/Left prediction
35
Mode 5: Vertical Right prediction
Mode 4: Diagonal DoWn/Right prediction Mode 6: Horizontal DoWn prediction Mode 7: Vertical Left prediction
generally less likely than horizontal and vertical prediction modes and generally more likely than diagonal prediction modes. For blocks that do not border discontinuities such as image
Mode 8: Horizontal Up prediction 40
some embodiments of the present invention may be
expressed, in general terms, as folloWs: vertical and horizon
Mode 3: Diagonal DoWn/Left prediction 45
Mode 6: Horizontal DoWn prediction Mode 7: Vertical Left prediction
prediction modes are more likely to produce a reduced pre
Mode 8: Horizontal Up prediction
diction error than intermediate angle prediction modes. 50
block or pixel prediction mode data is not available, the order established in some embodiments of the present invention
may be expressed, in general terms, as folloWs: DC prediction 55
horizontal prediction modes are more likely to produce a
reduced prediction error than diagonal prediction modes and that diagonal prediction modes are more likely to produce a
reduced prediction error than intermediate angle prediction modes.
60
In a ?rst set of embodiments as illustrated in FIG. 4, modes may be de?ned in order as folloWs:
Mode 0: Vertical prediction Mode 1: Horizontal prediction Mode 2: DC prediction Mode 3: Diagonal DoWn/Left prediction
Mode 4: Diagonal DoWn/Right prediction
It should be noted that the mode order may vary beyond these exemplary orders in various other embodiments of the present invention. In some embodiments of the present invention, the hori
zontal prediction (mode 0) and the vertical prediction (mode
mode is more likely to produce a reduced prediction error
than vertical and horizontal prediction modes and vertical and
Mode 4: Diagonal DoWn/Right prediction Mode 5: Vertical Right prediction
prediction mode is more likely to produce a reduced predic tion error than diagonal prediction modes and that diagonal For blocks near edges or boundaries or Where adjacent
In a ?fth set of embodiments, as illustrated in FIG. 8, modes may be de?ned in order as folloWs:
Mode 0: DC prediction Mode 1: Vertical prediction Mode 2: Horizontal prediction
edges or sWipe/sWath boundaries, the order established in tal prediction modes are more likely to produce a reduced prediction error than a DC prediction mode and that a DC
Mode 6: Horizontal DoWn prediction Mode 7: Vertical Left prediction
Mode 8: Horizontal Up prediction
data itself may have a greater tendency to be more consis
tently ordered. Furthermore, communication of modes may take advantage of coding techniques that reduce memory and bandWidth requirements. For example, the present inventors
Mode 0: Vertical prediction Mode 1: Horizontal prediction Mode 2: DC prediction Mode 3: Diagonal DoWn/Left prediction
65
1) may be reversed, if desired. Also, it is to be understood that the diagonal doWn/left prediction mode and the horizontal doWn prediction mode may be reversed, if desired. In addi tion, it is to be understood the diagonal doWn/right prediction
(mode 5), the vertical right prediction (mode 6), the vertical left prediction (mode 7), and the horizontal up prediction (mode 8) may be reordered, if desired. Further, it is desirable that the DC prediction is betWeen the mode O/mode 1 set and the mode 3/mode 4 set, but may be located betWeen mode 3/mode 4 set and mode 5/mode 6/mode 7/mode 8 set, if desired, or any other location. Moreover, the angled modes 3-8 may be renumbered as desired Without signi?cant impact
on the encoding e?iciency.
US RE43,567 E 8
7
(1) If both block A and block B are “outside” (e.g., not
In some embodiments of the present invention, the predic tion modes may be reordered for all of the respective blocks
available), only DC prediction (mode 2) is permitted, there fore the intra prediction mode order for block C is (2) If blockA is “outside” (e.g., not available) and block B
(e. g., those blocks using the described prediction scheme) using such a prediction basis. In addition, less than all of the
is not “outside”, only DC prediction (mode 2) and horiZontal prediction (mode 0) are permitted for block C, therefore;
respective blocks (e.g., those blocks using the described pre diction scheme) may use such a prediction basis, for example, more than 50%, 75% or 90%, if desired. Also, the order of the
(i) if block B is 2, intra prediction mode order for block C
prediction modes may be the same or varied for different
(ii) otherWise, intra prediction mode order for block C is
blocks. Further, the reordering of each of the modes of such a
{0, 2}.
prediction basis (e.g., in a predetermined consistent manner)
(3) If blockA is not “outside” but block B is “outside”, only
is preferably at least 5 modes, 6 modes, or 7 modes, With the remaining being ordered in any other manner. In addition, the
DC prediction (mode 2) and vertical prediction (mode 1) are permitted for block C, therefore (i) if blockA is 2, intra prediction mode order for block C
order of the prediction modes is preferably 0, 1, 2, 3, 4, 5, 6, 7, 8. Other prede?ned ordering of the prediction modes may likeWise be employed.
is {2, 1}; (ii) otherWise, intra prediction mode order for block C is
Some embodiments of the present invention may comprise
{1, 2}.
one or more data tables for organiZation of mode data. With
the modes being generally arranged in an ordered manner, this may be used together With each cell in a data table, to
20
provide a more ordered set. For example, each entry in the
data table may include the ordered set of numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Alternatively, the ordered set of numbers in the data table may include 5, 6, 7, 8, or 9 sets of ordered numbers for each entry in the data table. For example, the data table entries may include the folloWing sets of data entries {1,
order for block C is {intra prediction block mode A, intra prediction block mode B, other modes in ascending
order}; 25
2, 3, 5, 7}; {0, 1, 2, 3, 4, 5, 6}; {0, 1, 3, 5, 6, 7, 8}, Where each
(iii) if the prediction mode of blockA equals the prediction
Alternatively for example, the data table entries may include 30
5, 6}; {0, 1, 3, 5, 6, 7, 8}, Where each set is included in at least
For example, if the prediction mode of blockA is 3 and the prediction mode of block B is 1, then intra prediction mode
ability than knoWn data table methods, Which decreases 35
The predetermined manner of the ordering of the sets of data entries should be independent of the prediction modes of
adjoining sets of pixels (e.g. macroblocks). It is to be under stood that the data table may be “static” in nature or may be
effectively dynamically generated, in Whole or in part, When needed based upon patterns in the data. Accordingly, a math ematical equation or an algorithm may be used to determine the entries, Which in this case the “table” could be created by such a technique. Accordingly, a “data table” as used herein is not merely restricted to a static table, but further includes such a set of values, hoWever determined, that are used for such
40
of occurrence, then the automatic arrangement of the remain ing modes of occurrence Will still be generally arranged in the proper sequence. The ordering of the sequence from higher to loWer probability increases the likelihood of the proper pre
ments may likeWise be used. 45
Unfortunately, the substitution of the previous mode num
Conceptually the aforementioned selection scheme is based upon the principle that if the prediction of blockA is X and the prediction of block B is Y, then it is likely the predic tion of block C is X orY. The prediction for X and/orY is located at the start of the list and the remaining modes are
sequentially listed thereafter.
bers With the neW mode numbers (e.g., a substitution of num
Data In contrast to the generally unordered set of data shoWn, even With substitutions, the present inventors came to the
order for block C is {1, 3, 0, 2, 4, 5, 6, 7, 8}. With the modes arranged in a generally decreasing likelihood (or increasing)
diction toWard the front. With entropy encoding this decreases the resulting encoded bit stream. Other arrange
prediction. bers into the cells of knoWn data tables), While perhaps an improvement, still results in a generally unordered set of data. Estimating a Pixel Prediction Mode Based onAdj acent Block
mode of block B, then intra prediction mode order for block C is {intra prediction block mode A, other modes
in ascending order}.
25%, or 35%, or 50%, or 75%, or 90%, or more, ofthe cells. In this manner, the table Will have signi?cantly more predict
memory requirements.
(ii) if the prediction mode of block A is greater than the prediction mode of block B, then intra prediction mode order for block C is {intra prediction block mode B, intra prediction block mode A, other modes in ascending
order};
of the numbers in the set are of increasing numerical value.
the folloWing sets ofdata entries {1, 2, 3, 5, 7}; {0, 1, 2, 3, 4,
(4) If neither block A nor block B is “outside”, (i) if the prediction mode of block A is less than the pre diction mode of block B, then intra prediction mode
50
Stated another Way, When the prediction modes of A and B are knoWn (including the case that A or B or both are outside
the slice) the most probable mode of C is given, namely, the minimum of the modes used for blocks A and B. If one of the blocks A or B is “outside” the most probable mode is equal to 55
prediction mode 2. The ordering of prediction modes
further realiZation that the most likely prediction mode should be ordered ?rst, the second most likely prediction
assigned to blocks C is therefore the most probable mode
mode ordered second, if desired, folloWed by the remaining
Embodiments of the present invention may be described With reference to FIG. 9. In these embodiments, a target block
folloWed by the remaining modes in the ascending order.
modes in a predetermined manner. The predetermined man
ner should be independent of the prediction modes of adjoin ing macroblocks. The preferred order of the remaining modes
60
should be in a decreasing likelihood of occurrence of the
remaining modes (mo st likely prediction mode, and if desired, second most likely prediction mode). Based on the intra prediction modes of block A and block B, as shoWn in FIG. 1, the intra prediction mode order for block C may be de?ned as folloWs:
65
is selected 50 for prediction. A prediction mode used for prediction of a ?rst adjacent block, Which is immediately adjacent to said target block, is then determined 52. A predic tion mode used for prediction of a second adjacent block, Which is also adjacent to said target block is also determined 54. These adjacent block prediction modes are then examined 56 to determine Which is more likely to produce a lesser prediction error.
US RE43,567 E 9
10
In other embodiments of the present invention, as illus trated in FIG. 10, a set of prediction modes is ordered 58 according to the modes’ likelihood of producing a lesser prediction error. A target block is selected 60. The prediction mode used for a ?rst adj acent block is determined 62 and the prediction mode used for a second adjacent block is also
the next element in the order represents the prediction mode that is the next most likely to yield a lesser prediction error
determined 64. These tWo prediction modes are then exam ined 66 to determine Which occurs ?rst in the ordered set of
described above. This estimate is determined using adjacent block data. Generally, the estimate is the prediction mode
modes thereby corresponding to the mode With the higher
used in one or more adjacent blocks that is likely to yield a
likelihood of producing a lesser prediction error. In further embodiments of the present invention, as illus trated in FIG. 11, a set of prediction modes is ordered 68 by likelihood of producing a lesser prediction error. These modes in the ordered set are then associated 70 With numeri cal values such that modes With a higher likelihood of pro ducing a lesser prediction error are associated With loWer numerical values. The mode used to predict a ?rst adjacent block is then determined 72 and the mode used to predict a
lesser prediction error. HoWever, the estimate may be deter mined in other Ways. When suf?cient adjacent block predic
and so on to the last element in the order, Which represents the
prediction mode in the order that is least likely to yield a lesser prediction error. A prediction mode estimate is also determined 104, as
tion mode data is not available, such as at an image edge or a
slice boundary, a prediction mode for the target block may be estimated based on the lack of one or more adjacent blocks or
their prediction mode data. In many cases, a DC prediction mode Will be estimated When adjacent block data is limited or unavailable. In some embodiments, once the estimated prediction mode
second adjacent block is also determined 74. These adjacent block modes are then examined to determine Which mode is associated With a loWer numerical value. This mode is desig
is estimated, the estimated prediction mode may be placed 20
106 into the mode order as the mode most likely to yield a lesser prediction error. In some embodiments, this Will be the ?rst mode in the order or the mode associated With the loWest numerical value.
25
take precedence over the pre-selected mode order. In some of these embodiments, as illustrated in FIG. 14. a pre-selected mode order is designated 110 at the encoder and the decoder.
nated as the estimated mode for prediction of the target block. In still further embodiments, as illustrated in FIG. 12, a set
of prediction modes is ordered 78 by likelihood of producing a lesser prediction error. These modes in the ordered set are
then associated 80 With numerical values such that modes With a higher likelihood of producing a lesser prediction error are associated With loWer numerical values. An attempt 82 is made to determine the mode used to predict a ?rst adjacent block and an attempt 84 is made to determine the mode used to predict a second adjacent block. If the prediction mode
In other embodiments, the estimated prediction mode may
This order comprises a set of prediction modes arranged in 30
used to predict the ?rst adjacent block is not available 86, a default prediction mode, such as a DC prediction mode, may
diction mode is determined at the encoder and the decoder according to the same algorithm or method. The encoder also
determines the actual best prediction mode 114 for predicting
be designated 90 as an estimated prediction mode for the
target block. Also, if the prediction mode used to predict the second adjacent block is not available 88, a default prediction
35
a pixel based on motion vectors or other knoWn techniques.
40
The encoder may, then, compare 116 the actual best predic tion mode to the estimated prediction mode to determine Whether they are the same. If the estimated prediction mode is the same mode as the actual best prediction mode, the encoder may signal to the decoder that the estimated prediction mode is to be used 118. In some embodiments, this estimated pre diction mode signal may be performed With a l-bit ?ag to signify Whether the estimated mode is to be used on not. If the estimated prediction mode is not the actual best
mode, such as a DC prediction mode, may be designated 90 as an estimated prediction mode for the target block. When the
adjacent block prediction modes are available, these adjacent block modes may be examined to determine Which mode is associated With a loWer numerical value. This mode is then designated 92 as the estimated mode for prediction of the
target block. Modi?cation of Prediction Mode Order Based on Adjacent Block Data In some embodiments of the present invention the predic tion mode orders described above, Which have been deter
order of likelihood of yielding a lesser prediction error or some other order. An estimated prediction mode is also deter mined 112 based on adjacent block data. This estimated pre
45
mined independently of the adjacent block data, may be modi?ed With adjacent block data. Prediction mode estimates determined With reference to adjacent block data can be
50
inserted into prediction mode orders to modify the orders to re?ect the additional information obtained from adjacent block data. In some of these embodiments, a prediction mode estimate, based on adjacent block data, can be inserted directly into a
55
prediction mode, the encoder may signal to the decoder that another mode may be used 120. This may be performed by reference to the pre-established mode order. The encoder may determine Which mode in the mode order is mo st equivalent to the actual best prediction mode and signal the decoder to use that mode. When an ordered set of prediction modes is used, the set order may be rearranged once further data is obtained. For example, an ordered set of prediction modes may be reor dered When an estimated prediction mode is determined or When a best actual prediction mode is determined. In these
prediction mode order set. Typically, the prediction mode
cases, the modifying mode may be interjected into the
estimate Will be inserted or prepended at the front of the
ordered set, placed ahead of the ordered set or, in some cases, removed from the ordered set. In some embodiments of the present invention, each mode in the mode order may be associated With a numerical value
prediction mode order at the position of the mode most likely to produce a reduced prediction error. HoWever, in some
embodiments the estimate may be inserted at different posi tions in the mode order. In some embodiments of the present invention, as shoWn in FIG. 13, a prediction mode order is selected 102 Wherein the
60
according to the order. In these embodiments, the numerical value associated With the mode to be used may be sent to the decoder to signal the decoder to use that prediction mode. In some of these embodiments, as illustrated in FIG. 15, a mode
prediction mode order elements may be arranged according to their likelihood of producing a lesser prediction error. In
other Words, the ?rst element in the order represents the prediction mode most likely to yield a lesser prediction error,
65
order comprising 9 prediction modes may be selected 130.An estimated prediction mode based on adjacent block data, and Which is one of the 9 modes in the order, may also be deter
US RE43,567 E 11
12 d) receiving a second prediction mode that has been used for encoding a second adjacent block, said second adja cent block being adjacent to said target block; determining an estimated prediction mode among said ?rst prediction mode and said second prediction mode, Wherein said estimated prediction mode is the prediction mode associated With the lesser value; and calculating an actual prediction mode based on target block content analysis and comparing said actual pre diction mode to said estimated prediction mode.
mined 132. A best prediction mode may also be determined 134 by motion vector methods or other methods. The best prediction mode may then be compared to the estimated prediction mode 136. If the estimated prediction mode is substantially the same as the best prediction mode, the decoder may be signaled With a l-bit designator to use the
estimated prediction mode, Which is already identi?ed at the decoder. If the estimated prediction mode is not equivalent to
the best prediction mode, the estimated prediction mode is essentially eliminated from the mode order 140. This elimi
nation may be performed by re-ordering the set, skipping the
5. A method as described in claim 4 Wherein said estimated
estimated mode in the order or by other means. The remaining order Will effectively comprise 8 modes, Which can be repre sented by a 3-bit designator. This 3-bit designator may be sent to the decoder 142 to designate Which mode to use for pre diction.
pixel prediction mode is a DC prediction mode When at least one of said ?rst prediction mode and said second prediction mode are not available.
6. A method as described in claim 4 Wherein said set of
potential prediction modes comprises, in order:
The terms and expressions employed in the foregoing
a) one mode taken from a ?rst subset consisting of a hori
speci?cation are used therein as terms of description and not of limitation, and there is no intention in the use of such terms
and expressions of excluding equivalents of the features shoWn and described or portions thereof, it being recogniZed
20
that the scope of the invention is de?ned and limited only by the claims that folloW. We claim:
1. A method for determining an estimated pixel intra-pre diction mode, said method comprising:
25
a) ordering a set of prediction modes in an order;
b) selecting a target block for prediction mode estimation; c) determining a ?rst prediction mode that has been used for encoding a ?rst adjacent block, said ?rst adjacent block being adjacent to said target block; d) determining a second prediction mode that has been used for encoding a second adjacent block, said second adjacent block being adjacent to said target block; e) selecting one of said ?rst prediction mode and said
tion mode shall be used: 30
block being adjacent to said target block; 35
mode, said selecting being based on the relative posi tions of said ?rst and second prediction modes in said
order; and 40
target block; tion mode shall not be used: 45
mode are not available.
3. A method as described in claim 1 Wherein said estimated
pixel prediction mode is a DC prediction mode When at least one of said ?rst prediction mode and said second prediction mode is available, but coded in Inter prediction mode. 4. A method for determining an estimated pixel intra-pre
numerical value to decode said target block.
apparatus comprising: a) a plurality of prediction modes arranged in an order based on a likelihood of producing a lesser prediction error;
comprising:
b) a selector for selecting a target block for prediction mode 55
estimation; c) a ?rst determiner for determining a ?rst prediction mode that has been used to decode a ?rst adjacent block, said
?rst adjacent block being adjacent to said target block; 60
d) a second determiner for determining a second prediction mode that has been used to decode a second adjacent
block, said second adjacent block being adjacent to said
target block;
the sequence;
b) selecting a target block for prediction mode estimation; c) receiving a ?rst prediction mode that has been used for encoding a ?rst adjacent block, said ?rst adjacent block being adjacent to said target block;
i) receiving a mode numerical value indicating a predic tion mode to be used; and ii) using the prediction mode associated With said mode
8. An apparatus for estimating a pixel prediction mode, said
diction mode to be used for e?icient prediction mode com munication betWeen an encoder and a decoder, said method
a) ordering a set of potential prediction modes in an order of decreasing likelihood of producing a lesser prediction error by associating a sequential numerical value With each prediction mode such that the loWest numerical value is associated With the prediction mode most likely to produce a lesser prediction error and the prediction mode that is least likely to produce a lesser prediction error is associated With the highest numerical value in
ond adjacent block being adjacent to said target block; iii) determining an estimated prediction mode among said ?rst prediction mode and said second prediction mode, Wherein said estimated prediction mode is the prediction mode that is least likely to produce a lesser prediction error; and iv) using said estimated prediction mode to decode said d) When said indicator indicates that said estimated predic
2. A method as described in claim 1 Wherein said estimated
pixel prediction mode is a DC prediction mode When at least one of said ?rst prediction mode and said second prediction
i) determining a ?rst prediction mode that has been used for encoding a ?rst adjacent block, said ?rst adjacent
ii) determining a second prediction mode that has been used for encoding a second adjacent block, said sec
second prediction mode as an estimated prediction
f) calculating an actual prediction mode based on target block content analysis and comparing said actual pre diction mode to said estimated prediction mode.
Zontal prediction mode and a vertical prediction mode; b) the other mode of said ?rst subset; and c) a DC prediction mode. 7. A method for determining a pixel intra-prediction mode, said method comprising: a) selecting a target block for prediction mode estimation; b) receiving an actual prediction mode indicator, Wherein said actual prediction mode is based on target block content analysis; c) When said indicator indicates that an estimated predic
65
e) a selector for selecting an estimated prediction mode for said target block from among said ?rst prediction mode and said second prediction mode based on the locations of said ?rst and second prediction modes in said order; and
US RE43,567 E 14
13 l) a calculator for calculating an actual prediction mode based on target block content analysis and comparing said actual prediction mode to said estimated prediction mode.
14. A methodf‘or selecting a numberedprediction modef‘or efective estimation of an estimated pixel intra-prediction
9. A computer-readable medium comprising computer executable instructions for estimating a pixel prediction
giving ascending mode numbers toprediction modes in the
mode to be usedf‘or e?icientprediction mode communication between an encoder and a decoder, said method comprising:
order ofa vertical prediction mode, a horizontal predic tion mode, and a DC prediction mode, wherein the vertical prediction mode takes a pixel value of a
mode, said instructions comprising the acts of: a) ordering a set of prediction modes in an order based on a likelihood of producing a lesser prediction error;
block adjacent to an upper side of a block to be encoded as a prediction value,
b) selecting a target block for prediction mode estimation; c) determining a ?rst prediction mode that has been used for encoding a ?rst adjacent block, said ?rst adjacent block being adjacent to said target block; d) determining a second prediction mode that has been used for encoding a second adjacent block, said second adjacent block being adjacent to said target block; e) selecting one of said ?rst prediction mode and said second prediction mode as an estimated prediction mode based on the relative positions of said ?rst and second
the horizontal prediction mode takes a pixel value of a blockadjacent to a left side of‘the block to be encoded as aprediction value, and the DCprediction mode takes an average value of‘the
pixel value of‘the block adjacent to the upper side of the block to be encoded and the pixel value of the block adjacent to the left side of the block to be encoded as a prediction value; 20
prediction modes in said order; and l) calculating an actual prediction mode based on target block content analysis and comparing said actual pre diction mode to said estimated prediction mode. 10. A method as described in claim 7 further comprising designating a DC prediction mode as an estimated prediction mode if at least one of said ?rst prediction mode and said second prediction mode are not intra-coded. 11. A method as described in claim 7 further comprising designating a DC prediction mode as an estimated prediction mode if at least one of said ?rst prediction mode and said second prediction mode are unavailable. 12. A method as described in claim 4 Wherein said ordering
is performed such that the modes most likely to yield a loWer
actually been used for encoding a first adjacent block, said?rst adjacent block being adjacent to an upper side
of said target block; 25
30
35
prediction error are associated With the loWest numbers.
13. A methodfor selecting a numbered prediction modefor efective estimation of an estimated pixel intra-prediction mode, said method comprising: giving ascending mode numbers toprediction modes in the order ofa vertical prediction mode, a horizontal predic tion mode, and a DC prediction mode, wherein
the vertical prediction mode takes a pixel value of a 40
block adjacent to an upper side of a block to be encoded as a prediction value,
the horizontal prediction mode takes a pixel value of a blockadjacent to a left side of‘the block to be encoded as aprediction value, and the DCprediction mode takes an average value of‘the 45
pixel value of‘the block adjacent to the upper side of the block to be encoded and the pixel value of the block adjacent to the left side of the block to be encoded as a prediction value;
50
b) identi?1ing a target blockf‘or prediction mode estima tion; c) receiving a prediction mode indicator indicating whether or not an estimated prediction mode shall be
encoded as a prediction value;
identi?1ing a target blockf‘orprediction mode estimation; identi?1ing a mode number of‘a?rst prediction mode that has actually been used for encoding a first adjacent block, said?rst adjacent block being adjacent to an upper side of said target block; identi?1ing a mode number of‘a second prediction mode that has actually been usedf‘or encoding a second adja cent block, said second adjacent block being adjacent to a left side of‘said target block; and selecting aprediction mode having the smaller mode num ber between the first prediction mode and the second prediction mode as the estimatedprediction mode of‘the target bloclc
15. A methodf‘or selecting a numberedprediction modef‘or efective estimation of a pixel intra-prediction mode, said method comprising: a) giving ascending mode numbers to prediction modes in the order of a vertical prediction mode, a horizontal
the horizontal prediction mode takes a pixel value of a block adjacent to a left side of‘the blockto be encoded as aprediction value, and the DC prediction mode takes an average value of‘the
pixel value of the block adjacent to the upper side of the block to be encoded and the pixel value of the block adjacent to the left side of the block to be
receiving a mode number of‘a secondprediction mode that has actually been usedfor encoding a second adjacent block, saidsecond adjacent blockbeing adjacent to a left side of said target block; and selecting aprediction mode having the smaller mode num ber between the first prediction mode and the second prediction mode as an estimated prediction mode ofthe target block.
prediction mode, and a DC prediction mode, wherein
the vertical prediction mode takes a pixel value of a block adjacent to an upper side of a block to be encoded as a prediction value,
identi?1ing a target blockf‘orprediction mode estimation; receivinga mode number of‘a?rstprediction mode that has
55
used to decode the target block; d) when said indicator indicates that an estimatedpredic tion mode shall be used: i) identi?1ing a mode number of‘a?rstprediction mode
that has actually been usedfor encoding a first adja cent block, said?rst adjacent block being adjacent to 60
an upper side of said target block; ii) identifying a mode number of a second prediction mode that has actually been usedf‘or encoding a sec
ond adjacent block, said second adjacent block being adjacent to a left side of‘said target block;
iii) selecting aprediction mode having the smaller mode 65
number between the first prediction mode and the second prediction mode as an estimated prediction
mode of‘the target block; and
US RE43,567 E 15
16
iv) using said estimatedprediction mode to decode said
e) a selectorfor selecting a prediction mode having the smaller mode number between the first prediction mode
target block;
and the second prediction mode as an estimated predic
e) when said indicator indicates that said estimatedpre
tion mode of the target block. 17. A computer-readable medium comprising computer executable instructions for selecting a numbered prediction
diction mode shall not be used:
i) receiving a mode information indicating aprediction mode to be used; and
ii) using the prediction mode indicated by said mode
modefor ejfective estimation ofa pixelprediction mode, said
information to decode said target bloclc 16. An apparatus for selecting a numbered prediction
assigning ascending mode numbers toprediction modes in
instructions comprising the acts of' the order of a vertical prediction mode, a horizontal
modefor @fective estimation ofa pixelprediction mode, said apparatus comprising:
prediction mode, and a DC prediction mode, wherein the vertical prediction mode takes a pixel value of a
a) an assignorfor assigning ascending mode numbers to prediction modes in the order of a vertical prediction mode, a horizontal prediction mode, and a DC predic tion mode, wherein
block adjacent to an upper side of a block to be encoded as a prediction value,
the horizontal prediction mode takes a pixel value of a blockadjacent to a left side ofthe block to be encoded as aprediction value, and the DCprediction mode takes an average value ofthe
the vertical prediction mode takes a pixel value of a block adjacent to an upper side of a block to be encoded as a prediction value,
pixel value ofthe block adjacent to the upper side of
the horizontal prediction mode takes a pixel value of a block adjacent to a left side ofthe blockto be encoded as aprediction value, and the DC prediction mode takes an average value ofthe
pixel value of the block adjacent to the upper side of the block to be encoded and the pixel value of the block adjacent to the left side of the block to be
the block to be encoded and the pixel value of the block adjacent to the left side of the block to be encoded as a prediction value;
identi?1ing a target blockforprediction mode estimation; identi?1ing a first prediction mode that has actually been 25
encoded as a prediction value;
block;
b) a first identifierfor identi?1ing a target blockfor predic tion mode estimation;
c) a second identi?erfor identi?1ing a?rstprediction mode that has actually been used to decode a first adjacent
block, said?rst adjacent block being adjacent to an upper side of said target block; d) a third identifier for identifying a second prediction mode that has actually been used to decode a second
adjacent block, said second adjacent block being adja cent to a left side ofsaid target block; and
usedfor encoding a?rst adjacent block, said?rst adja cent block being adjacent to an upper side ofsaid target
35
identi?1ing a second prediction mode that has actually been used for encoding a second adjacent block, said second adjacent block being adjacent to a left side of said target block; and selecting aprediction mode having the smaller mode num ber between the first prediction mode and the second prediction mode as an estimated prediction mode ofthe target block.